Evaluating the hydrogen supply chain so far—An assessment and review of critical aspects for an economy supported by a “hydrogen infrastructure”

This paper critically evaluates hydrogen's role as a decarbonization strategy, addressing key technical and economic constraints that challenge its widespread adoption. We analyze inherent energy conversion losses that make hydrogen-based systems less efficient than direct electrification for many applications, along with persistent issues in scalable storage, distribution, and production costs. The analysis highlights the specific limitations of the 2 primary production pathways: green hydrogen, constrained by the high cost of electrolyzers and the sourcing of critical materials, and blue hydrogen, which faces concerns regarding methane leakage and the long-term viability of carbon capture technologies. We argue that hydrogen's most effective application is as a strategic enabler for hard-to-abate sectors, such as heavy industry and long-distance transport. The paper also explores innovative concepts like thermochemical looping with metal oxides and the integration of hydrogen into a circular carbon economy as pathways to enhance its efficiency and economic viability. Ultimately, the transition to a global hydrogen economy is a complex, multi-decade undertaking that necessitates a pragmatic, targeted approach with substantial investment and coordinated international policy to realize its full potential.